Engraving is the process of permanently cutting lines into a metal surface --- whether it's to personalise the bike or help secure the bike as belonging to you. The latter is a significant motive, as according to the website Bicycle Theft, most stolen bikes are never returned to the proper owners because of a lack of identifying info. If this is your reason for engraving, you should also engrave either the bike's registration number or your state ID number into two different places on your frame.
Write the engraving numbers and letters on the places you want to engrave using the dry-erase marker. Pick two places on your frame, such as the down tube and the bottom bracket for example. Generally, some thieves find the first engraved ID spot and file it off. However, they might not necessarily look for a second location, increasing your chances of recovery when your bike is stolen.
Wear your goggles and dust mask. Place your bike against a wall or lay it down on the floor to keep it steady. Plug in the engraver tool.
Use the engraver tool to start tracing over the marker. Make sure to keep your hand as steady as possible. Gently and slowly press down the engraving tool and occasionally brush away the metal dust.
Remove your mask and goggles when your are done engraving on both places on your bike. Wipe down the engraved numbers using alcohol imbibed cotton balls and clean off the remaining marker and metal dust.